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By Marco Túlio Santiago Ferreira, Nilton Carlos Torquato, Washington Pirete da Silva

In 2005, with the significant reduction of iron content in the “Quadrilátero Ferrífero” reserves, Vale began the study of alternatives for the tailings disposal in other structures, that are not tailings dams. In 2011, after bench-scale and pilot-scale tests, it was defined to implement the project "Alternative methods for tailings disposal", including the construction of experimental drainage piles to get mineral and geotechnical process parameters for future projects. The result of this study shows that it is technically possible to replace traditional tailings disposal (dams), to dry stacking, with the proportion up to 20% of ultrafine tailings in the total tailings composition, however, this study is in evolution and the scale of the project / pile is being gradually increased to guarantee a good performance for the mineral and geotechnical process.

Oct 3, 2019

By Silvio Pereira Diniz Maranha, Evandro Costa e Silva

The disposal of coal tailings in an economically and environmentally sustainable way can be considered one of the biggest challenges for coal producers due to their physical, chemical and mineralogical characteristics and the significant annual volumes generated. The processing and utilization of coal fines is recognized as one of the great technical challenges of this industry. These challenges become even greater when it comes to the use of tailings from coking coals. This is due to the potential changes in their various properties, variability of these characteristics along the deposits, the handling and dewatering aspects of the products and the granulometric restrictions imposed by the coking plants for the coals to be handling and coking. This work presents the current stage of project development for the use of a metallurgical coal fines dam, addressing the general concept of the project, the exploratory sampling program and the characterization of the tailings for process and product development purposes after processing. It aims at the characterization and the carbonization tests for product development, the mining method considered, product alternatives, suitable to the market, to be generated and the next steps.

Oct 3, 2019

By Hiago Antunes Amador de Oliveira, William Pratt Rogers, Aaron Young

Monitoring systems are highly critical components in the safety of tailings storage facilities (TSF). Internet of things (IoT) platforms present a unique way to improve TSF monitoring systems. Since there are so many available IoT technologies, this conference paper aims to create a focused list of IoT options for improving TSF safety. To achieve this aim, a brief qualitative review of available literature and state of the art technologies is presented in Section 2. The article further assists this aim by summarizing the benefits of IoT platforms which have been found in the literature. With respect to findings, literature suggests that while sensor technologies have existed as solutions for tailings dams for many years, IoT greatly reduces the cost of deploying, monitoring, maintaining, and gaining insight from these sensors. Additionally, IoT removes the need for manual data collection from sensors, enabling the monitoring of tailings dams from miles away and the use of new sensor technologies. Therefore, as a conclusion, this article recommends that IoT capable monitoring systems be considered for use in TSF monitoring.

Oct 3, 2019

By Elen Mancini Santi Paulettor, Vinicius Calheiros, Eduardo de Oliveira Cabral

At this paper, Eirich will present its new tool for sinter analysis integrated to the sintering control system. For stabilization and optimal, continuous control of the sintering process, QualiMaster MT1, a device was developed which guarantees fully automatic representative sampling and material analysis and thus a high and stable sintering quality. Mining tailings often has a considerable proportion of valuable substances. In addition to this work, we will also present our mixing technology that allows the economic recovery of these mining tailings.

Oct 1, 2019

By André Carlos Silva

Dewatering stage is among the most important industrial unit operations, and is wide adopted in many different industries, due the fact that a large portion of industrial products is produced using suspensions of solids in liquids. Nowadays the mineral processing tailings disposal is a big problem due the environmental degradation produced. The phosphate rock processing in Anglo American Phosphate Brazil, situated in Catalão/Go/Brazil, generates around 180 t/h of tailings for a plant feed of 480 t/h (approximately 37,5% of the processing plant feed), with 5 to 10% of solids and approximately 14% of P2O5. Nowadays the tailings are sent direct to the tailings dam. The present work proposes the paste production using with the tailings from phosphate rock processing plant divide in two different stages. The first one composed by the free settling of the material in presence of industrial flocculants in a graduated cylinder with 2.0 L of internal volume for one hour, in the same way it must occur in conventional thickeners. After that time, the clarified liquid was drained and the remaining pulp was sent to the second stage consisting in the tailings vacuum filtration. Ten different flocculants and nine different filter media were tested. The found results were satisfactory for paste tailings production with solids percentage around 65%.

Aug 8, 2018

By Junio Simões Pereira, Carlos Magno Nascimento, Frederic Yann Armache Braga, Luiz Cláudio Monteiro Montenegro

Given the current scenario experienced by Brazilian mining industry, the study and development of technologies that enable a more secure and controlled disposal of tailings has gained significant relevance. Among the various alternatives and disposal methodologies, Anglo American has been developing tests on three study fronts: dewatering polymers, hydrocyclone dewatering and pulp filtration. The first two fronts are intended to optimize the way of occupying the existing tailings dam. The filtering is intended to reduce the mass transfer to the reservoir, extending the life time of the existing structure. The studies were divided into laboratory, pilot and industrial phases, aiming at proving applicability and scheduling for a definitive future installation. Until this moment, all tests have demonstrated gains and potentials of applicability.

Oct 3, 2019

By Paula Maria Gomes Cunha Leão, Flávio de Castro Dutra, Fabrício Vilela Parreira, Silvio Maranha

In the iron ore beneficiation, tailings are inherent in the concentration processes to which the ores are subjected for the production of commercial products. The large generation of tailings has been motivating the study of technological alternatives for its reuse, with the development of processes that contemplate the concentration of fine ore particles present in the tailings, such as the reintroduction of these particles in the process of manufacture of the iron and steel itself, through the agglomeration techniques such as briquetting. The aim of this article is to study the technical feasibility of the production of iron ore tailings and coking coal briquettes for use in reduction reactors, through a systematic review of the literature on agglomeration, briquetting and self-reduction processes, covering the main variables that influence the production of high quality briquettes, such as binders use, binder behavior of coking coal, coal granulometry, iron ore and coal proportion, compacting pressure and temperature of thermal treatment and the effects of these variables on briquettes final properties.

Oct 1, 2019

By Wellington Ribeiro Moreirar, Anderson Willian Henrique Santini, Lívia Mara Cândido, Adriano Raimundo Totour

Rejects generated in mining projects usually do not have associated economic value. Most of the ore beneficiation processes occur by wet process with a higher fraction of water and ultrafine granulometry, which makes it difficult to dispose of these wastes. In 2013, studies with new tailings treatment and filtering technologies were initiated with the objective of eliminating the disposal of the residue generated in the industrial process to wet in dams. In this context, we tried to evaluate an alternative for the dewatering of the sludge and the tailings, aiming at their disposal in piles. Essentially, we sought to consolidate the application of the high-pressure filtration technology for the effluent dewatering, in order to allow its transport and its disposal in a sustainable way. The studies performed in a pilot filter showed good performance and allowed the industrial implantation. The studies and geotechnical indications of composite tailings (flotation and sludge) make it possible to dispose of the tailings in piles due to their better values of humidity, which allows them to be safely stacked.

Oct 3, 2019

By Moisés Paulo Teixeira

The use of tailings for the synthesis of new materials is a worldwide concern today. This paper approaches the utilization of tailings of soapstone (steatite) in order to produce ceramics. The results show that the addition of soapstone in a ratio over 20% in the ceramic mass has enhanced the bending resistance of the ceramic samples when they were fired at temperatures of 900°C or 1000°C.

Oct 30, 2017

By Cesar Santos, Marcelo Duarte Silva, Ediron Antônio Lage, Fábio Silva dos Santos

Ceramic filtration technology, despite consuming about 90% less energy than conventional vacuum filters and producing clean water ready for reuse, faced a big challenge that put in doubt its technical and economic viability. In 2015, the production of pellet feed in this last stage of the process of the Minas-Rio Complex of Anglo American was impacted by deep fillings in the filter medium. The chemical regeneration process indicated by the filter manufacturers did not have the necessary effect. SUEZ then carried out a research work on the potential causes and indicated specialty chemicals. After an intense work of the Anglo American technical team supported by SUEZ, an efficient regeneration methodology was developed. From this reference, SUEZ received another 03 similar challenges with ceramic filters. Among them, the Herculano Mineração Dry Stacking pioneer project, which until 2017 could not process more than 20% of the tailings generated in the pellet feed concentration process. Following adaptations in the regenerative methodology as a function of the mineral characteristics facilitated by the development of a pilot backwash system, success was achieved, providing a condition for production of 3.0Mtpy without the use of tailings dam and with continued decline in the unit cost of the tailings filtration operation.

Oct 3, 2019

By Thokozani Lehae Hanes Malinga

O complexo Minas-Rio da Anglo American iniciou suas operações em agosto de 2014. A usina de tratamento produziu, em 2016, cerca de 15,5 milhões de toneladas secas de concentrado. O minério, explorado no município de Conceição do Mato Dentro (MG), passa pelas etapas de cominuição, classificação, concentração e separação sólido-líquido antes de ser bombeado por 529 km até o município de São João da Barra (RJ), onde é filtrado, estocado e embarcado para exportação. A lama e o rejeito da flotação são enviados para um espessador de 90 metros de diâmetro. Testes de sedimentação em bancada mostraram o efeito positivo da sedimentação dessa mistura de lamas e rejeito. A lama, composta predominantemente por partículas finas de hematita e argilo minerais, se adere a ao quartzo do rejeito, que possui maior diâmetro. Apesar dessa mistura aumentar a velocidade de sedimentação, ela propicia a formação de uma espuma com elevada estabilidade, devido a presença de finos da deslamagem e espumante da flotação. Foram feitos testes de bancada objetivando-se avaliar o efeito da retirada do rejeito da alimentação do espessador. A partir dos resultados foram traçados cenários com diferentes participações desse material e suas implicações no processo de sedimentação foram estimados.

Oct 30, 2017

By César Junior dos Santos, Fábio da Silva dos Santos, Robson Rodrigues Martins

Tailings disposal has been a recurring theme of research in the major mining process development centers. This is due to the great interest of companies in reducing the social and financial impacts of their environmental liabilities. Another major driving force behind the search for new alternatives is the recent cases of environmental accidents in Brazil and abroad. According to the International Commission on Large Dam (ICOLD), two major accidents per year involving dams are reported worldwide. Hence, we realize that the analysis of the topic as well as the search for solutions becomes a challenge for both entrepreneurs and research institutions. In this work, a case study of the Herculano Mining will be carried out, working in the extraction and processing of iron ore. The main stages of the study are: technological characterization of tailings from the beneficiation process, analysis of filtration processes of this material for disposal in piles, bench tests and evaluation of the performance of the industrial facilities of the company in question. Herculano has an installed ceramic filtration equipment that faces operational difficulties in certain types of ore. At first, all the possibilities of adjusting this process will be analyzed so that it can filter the necessary mass of waste, acting in the rheology of the pulp (sedimentation, flocculation), regeneration of the ceramic plates and adjustments of the machine (filter), in order to obtain the best condition.

Oct 3, 2019

By Sandra Lúcia de Moraes

Uma característica do setor mineral é a movimentação de grandes volumes de materiais que, em função do teor do bem mineral contido e das particularidades do processo de beneficiamento, ao final gera grandes quantidades de rejeitos. O aproveitamento desses rejeitos é um tema que tem sido discutido e que foi fomentado após o acidente acontecido em 2015, com a barragem da Samarco em Mariana - MG. O trabalho denominado “Rejeitos da Mineração: Um olhar do cenário brasileiro” está estruturado em duas partes. A primeira parte destacou a importância econômica e social do setor mineral para o país. A segunda parte, apresentada neste artigo, aborda o nível de desenvolvimento tecnológico voltado ao aproveitamento dos rejeitos e quais novos usos têm sido propostos. Neste documento, os autores trazem também o fechamento dos levantamentos realizados e suscitam uma discussão visando estimular o desenvolvimento sustentável da mineração, por meio da criação de um novo negócio inserido na cadeia produtiva da mineração.

Oct 30, 2017

By Michael Breuer, Christian Mengel, Luis Acainas Caballero, Olaf Jepsen

Stability of the hot strip mill rolling process remains a main topic when it comes to processing thin and hard materials. Strip steering especially at the end of rolling and tail out rips are a main source of unscheduled down times in a hot strip mill. Main focus of this paper is the new X-Roll® Guide system to improve mill stability and quality. An overview of SMS group developments in the recent years regarding equipment and control strategies is given. The new side guiding system in the entry area of the finishing mill is introduced and explained with operational examples. The system provides reproducible conditions for the threading process and during rolling. Steering control has a direct benefit on the availability of the mill. New developments of the roll alignment control strategies based on roll force and mill stand entry guide force measurement will be presented. Additionally a camera based measuring system is introduced that generates a direct process feedback of the strip position. It provides together with the roll alignment control the necessary control parameters for adjusting the roll gap and guiding the strip correct centered through the mill. As a summary the SMS group system is explained combining all features.

Oct 1, 2019

By Li Shanqing, Xu Jianghua, Li Hongmei, Huang Peijie

Cold rolled high strength steel are playing a very important role in reducing automobile weight for energy saving and environment protection. In recent year, more and more high strength steel were manufacturing in steel company. But there are some problems in the cold rolling process for high strength steel products. Periodic thickness deviation especially in strip head or tail is an important one in these problems. In this paper, the reason of periodic thickness deviation was analysed and a new AGC algorithm called Property FFC for high strength steel in tandem cold rolling was developed. The application of this new algorithm shows that it can reduce the thickness deviation.

Oct 1, 2019

By Andrea Taurino

Innovation means implementing a new product or a product that has undergone significant improvement over time, in terms of method, form and performance. Innovation encompasses all the scientific, technological, organizational, financial and commercial steps that need to be taken to put it into operation. Innovation combined with research and development makes it possible to perfect the product with consistency over time. Taking inspiration from the bases developed by the Austrian economist Joseph A. Schumpeter back in 1911, Danieli came up with the concept of “Innovaction” – a combination of Innovation and Action, to refer to the development and advancement of various products for the steelmaking industry, including the loop laying head for wire rod.

Aug 17, 2017

By Claudio Fabbro

The increasing demand of wire rod high carbon grades for both small and large sizes are challenging the wire rod producers to enhance new technologies by combining high plant productivity and efficiency of superior quality finished products with extreme process flexibility. The possibility to change process route according to the final application of the rolled steel grade and to simplify production planning is one of the most important keys to success that distinguishes the mill plants developed by Danieli. This paper will focus on the most important metallurgical and process targets and on the in-line heat treatment technologies representing the core of Danieli know-how on high carbon grades production.

Jul 30, 2018

By Bruno Alves Resende, Antonio Adel dos Santos

Temperature, microstructure and dimensions are the main material parameters to be controlled during hot rolling of steel. Although thermal mathematical models have long been developed and applied for hot strip rolling, each Hot Strip Mill (HSM) must have its own model adapted to its facilities. Thus, a mathematical model for temperature evolution during rough rolling has been developed for the Usiminas HSM at Ipatinga Plant. The model achieved a high level of accuracy, which was assessed by comparing measured values of temperature at the hot strip mill entry with the calculated ones, the difference ranging from 9°C to 17°C. Application examples have shown that the slab can be occasionally stopped before start of rolling for as long as a couple of minutes without compromising its further processing. On the other hand, if the transfer bar stops after rough rolling even for short time, further processing in the HSM can be hindered, due to excessive temperature drop. In case of such abnormal line stop, the model can be used as a tool for decision-making to either continuing the planned rolling schedule or to changing the route, thus improving the overall rolling process.

Oct 1, 2019

By Norbert Asamer, Stefan Purrer

Depending on the product or the material grade, conventional deburring machines, such as e.g. with rotating hammers, are in many cases not capable to reliably or completely remove burrs from the edges of a continuously cast product. Burr, however, is generated at the front and/or tail ends of a slab, bloom or billet as a result from torch cutting. Likewise, traversal grinding of the slab’s rolling surfaces can also cause burr at the long side edges of the slab whereby such burr can even be more difficult to remove. Based on their experience and know-how with abrasive machining processes (abrasive cutting, high-pressure grinding) over a period of more than 50 years up to now, BRAUN has developed a highly flexible deburring grinding machine for applications which are too difficult for conventional deburring techniques. BRAUN’s deburring grinding machines were successfully introduced to the steel industry and have proven their worth under normal production conditions already. The subject paper describes the key features and advantages of BRAUN’s machine design and the operational results from the first already completed projects.

Oct 1, 2019

By Tatiana Salviano Gadelha

Rejeitos de mineração descartados na forma de polpa possuem, geralmente, grande quantidade de água e reutilizá-la no processo, por meio de operações de desaguamento mais eficientes é de grande importância para a implementação de projetos de menor impacto ambiental. O presente trabalho visa estudar as operações envolvidas no desaguamento de um rejeito de níquel, com o objetivo de principalmente a maximizar a recuperação de água de processo. Para tanto, foram avaliados: a influência da concentração de sólidos, uso e dosagem de floculante, pressão no filtro, o processo de filtração com e sem prensagem e a influência destas variáveis na umidade da torta e na recuperação de água. Os resultados mostraram que quanto maior a dosagem de floculante menor é a recuperação de água na filtragem; por outro lado, quanto maiores a concentração de sólidos e a pressão, maior a recuperação de água. Verificou-se a importância do uso da prensagem para maximizar a recuperação da água contida no sedimento, sendo possível comprovar que o rejeito de níquel floculado e filtrado com ?P de 6 bar com o uso de prensagem promoveu a recuperação de até 77% de água.

Aug 17, 2017